Massive surge gate is installed across Lake Borgne marshes

The Army Corps of Engineers' largest, and perhaps least-seen,
flood-protection project in the New Orleans area moved a step closer to
completion Thursday with the installation of a massive gate in the
barrier built across waterways near Lake Borgne.

View full sizeMichael DeMocker, The Times-PicayuneWorkers with the Army Corps of Engineers install a sector gate in the Inner Harbor Navigation Canal-Lake Borgne Surge Barrier on Thursday.

The 150-foot-wide steel gate is part of the nearly two-mile long Inner Harbor
Navigation Canal-Lake Borgne Surge Barrier, which aims to block a storm
surge before it can enter the Industrial Canal and threaten the Lower
9th Ward, St. Bernard Parish or other areas.

The wall cuts across
marshes near Lake Borgne where the Gulf Intracoastal Waterway and the
now-deauthorized Mississippi River-Gulf Outlet converge. At 25 feet
high, it is as tall as the storm surge from Hurricane Katrina when
it passed into the canal.

Corps officials hold up the surge
barrier as one of the primary examples of the forward defensive
strategy they said has been a significant consideration as they have
worked on the area's flood protection. The philosophy behind such a
system is to stop a surge well before it reaches the areas being
protected, said Col. Robert Sinkler, head of the corps' Hurricane
Protection Office.

"Everywhere in the system, we moved our primary line of defense as far from heavily populated areas as possible," Sinkler said.

In
the case of the $1.1 billion surge barrier, that means blocking a wall
of water 12 miles before it would reach downtown New Orleans and 8
miles before it would reach the Lower 9th Ward, Sinkler said.

In
addition to moving the main flood protection system away from homes and
businesses, the move has also allowed the corps to avoid building about
30 miles of primary levees or floodwalls in areas that are now
protected by the barrier.

"It blocks the avenues a storm surge would take entering into the heart of the city," corps spokeswoman Nancy Allen said.

The
sector gate is one of three entrances that will allow maritime traffic
to flow through the barrier and into the Industrial Canal. A 56-foot
wide vertical lift gate already has been installed at Bayou Bienvenue,
and a barge gate is being installed next to the sector gate.

The
barge gate is at the Avondale shipyards and will be moved into the area
when the Mississippi River level drops enough to allow safe navigation.

Although
installed, the gate has not yet been connected to the mechanical
systems that will allow it to open and close. For the duration of this
hurricane season, the gate will remain closed to provide protection,
Allen said.

The gate at the surge barrier is the second-largest
ever constructed by the corps and falls about 75 feet short of the
largest, which is installed on the other end of the Gulf Intracoastal
Waterway near Belle Chase.